Stoker alarm



' June 1, 1937. J. ROLAND STOKEH ALARM Filed April 2'7, 1955 IE 2m\ZMHIIIIMII/IM INVENTOR. db/r/v [Four/v0,

ATTORNEY-'5.

Patented June 1, 1932 UNITED STATES PATENT OFFICE Schwitzer-CumminsCompany,

Ind., a corporation Indianapolis,

Application April 27, 1935, Serial No. 18,535 7 Claims. (01. 171-311This invention relates to an automatic signal or alarm applicable tostokers to indicate failure of operation.

When the feed screw of a stoker is blocked for any reason, such as by arock, rail spike or other' obstruction becoming lodged therein, itsoperation is, necessarily, discontinued. To that end, stokers areusually equippedas a protection against overload, with various overloador pressure release devices that will operate to release the drive ordiscontinue it. Thus, in mechanically driven stokers, the driving pinmay be sheared or withdrawn, gears unmeshed or a clutch released. Again,the circuit to the electric drive motor may a be broken. In. stokersembodying hydraulic power transmissions there is provided a by-passvalve to relieve hydraulic pressurasuch as will prevent continueddriving operation of the screw feed while the driving motor continuesits operation.

It is the purpose of this invention to equip such device with an alarmwhich will call attention to the stoker should it become inoperativethrough obstruction or the like. Wherein attention is not calledthereto, the stoker may cease to function, allowing the fire to get lowor go out. In such instances such a situation may.result in substantialdamage, or perhaps merely discomfort. Thus, it is desirable to callattention to such condition by an alarm which will be effective,depending upon the character and purpose of the installation. As anexample, wherein a stoker is employed in a greenhouse and may be leftwithout attention for considerable lengths of time, it is desirable toprovide an alarm at a remote station, such as in the ofiice of thegreenhouse, to give warning that the stoker has stopped functioning. Bymeans of this invention there is provided a device for giving an alarm,either at the stoker or at the station remote therefrom, upon the stokerbecoming inoperative through an obstruction or the like. The alarm mayalso be equipped with means for breaking the circuit to the drivingmotor so as to prevent wear and tear on the parts and consumption ofcurrent during the non-operation of the stoker, all as will behereinafter more fully set forth and described.

The full nature of the invention will be understood from theaccompanying drawing and the following description and claims: Fig. 1 isa perspective view showing an application of one type of alarm. Fig. 2is a front elevation. of the alarmcontrol showing the wiring diagramtherefor. Fig. 3 is a front elevation of a portion of the alarmactuating inechanilm.

The invention is herein described as being applied to a hydraulic powertransmission of a stokeras more particularly set forth in Letters Patentto Carl J. Winkler and Herman E. Winkler, No. 1,968,188, issued July 31,1934. However, the invention may be likewise applied to other types ofstoker power transmissions, such as a gear driven stoker.

In the drawing there is illustrated a section III of the powertransmission housing which is provided on the forward face thereof witha switch box II. Mounted within said housing there is provided acylinder I2 into which oil is pumped by a pump driven 'by a motor I3,the piston in ,the cylinder I2 actuated by the pressure of the oil pumptherein driving the usual feed screw of the stoker through a pawl andratchet drive, the shaft of said feed screw extending through -a bearingI4 in the forward face of the housing, all as fully illustrated in theabove-mentioned Letters Patent.

Mounted on the cylinder I2 and in communication with the interiorthereof, there is provided a pressure control by-pass valve I5 which isillustrated in Fig. 1 of the above-mentioned Letters Patent indicated bythe numeral 46 and referred to therein as fdllows: Communicating withthe 2 upper portion of the cylinder there is a blow-off valve indicatedat 46 in Fig. l for relieving the pressure upon being excessive, such asmay be caused by an obstruction to the movement of the piston."

For ordinary domestic use and for local alarm. said by-pass valve I5 maybe provided with a whistle or any other construction therein which willproduce sufficient sound to attract attention. Said valve is constructedin the usual manner to withstand the normal pressure of the piston inthe operation of the stoker and only permit bypassing of the oil fromthe piston upon the pressure substantially exceeding normal pressure byreason of obstruction to normal driving operation, as is well understoodin the art.

For the purpose of giving alarm at a remote point, a cup I6 is mountedon a shaft H in such position with respect to the valve I5 as to receivethe full force of the oil forced therethrough upon the pressure in thecylinder being abnormally excessive due to obstruction. The forceexerted by the discharge of oil through the valve against the base ofthe cup I6 causes partial rotation of the shaft H which is mounted insuitable bearings and extends through the front face I0 into the switchbox II.

Mounted upon the forward end of the shaft 55 tion.

there is a trip lever ll provided with a latch I! on the outer endthereof. Pivotally mounted within the box ii there is a mercury switch20 supported by a plate 2|, the free end of which is supported by theshoulder of the latch I! on the lever I8. Said switch is so positionedin the box II that upon being released by the lever I! it will drop downto the position indicated by dotted lines to break one circuit and makeanother circuit, as will be hereinafter described. Slidably mounted toextend through the bottom of the switch box ii there is a plunger 22which may be manually manipulated to raise plate 2! carrying the switch20 so as to reset the switch after operation. Thus, after the switch hasbeen released by the latch l8 and the stoker trouble remedied, theplunger 22 may be pushed up to reset the switch in latched position.

The switch 20 has its pivoted ends connected to the motor II by the wire22 and to a source of energy 24 by a wire 25. The opposite or free endof the switch is connected by a wire 26 to a remotely placed alarm 21,the alarm being connected by a wire 28 with the source of current 24.Thus, when the mercury tube is supported in elevated position by thelever i8, the circuit through the motor is closed, causing operation ofthe stoker, while the circuit through the signal is opened. Uponoperation of the stoker being aflected by an obstruction such as tocause a blowoii of valve l5 and releasing oi the switch, its downwardlytilted position causes the circuit to the motor to be broken and thecircuit to the signal to be closed. This will call attention to the factthat the stoker is not operating and requires attention.

Other automatic controls may be electrically connected in the abovedescribed circuits as may be desired to include thermostatic controlsand kindling controls in the usual manner and as is well understood inthe art.

The invention claimed is:

1. In stoker mechanism, hydraulic pressure means for operating thestoker, an electric m0- tor to operate said pressure means, a reliefvalve for said pressure means, a switch in the circuit of said motor, amember operable by impact of pressure from said valve for operating saidswitch to deenergize said-motor, a signal, and a circuit including saidsignal and said switch, closed when said switch is moved 'to'motordeenergizing posi- 2. In stoker mechanism, hydraulic pressure meansfor operating the stoker, a motor to operate said pressure means, arelief valve for said pressure means, a signal, and a member operable byimpact of pressure through said relief valve for rendering said motorinactive and to simul taneously operate said signal.

3. In stoker mechanism, hydraulic pressure means for operating thestoker, a motor to operate said pressure means, a switch in the circuitof said motor, a lever for operating said switch, a relief valve forsaid pressure means, means operable by impact of pressure from saidvalve for operating said lever, a signal, and a cit-1 cuit includingsaid switch and said signal and,

closed when said lever has been operated by impact of pressure from saidvalve.

4. In an alarm device for stokers having a hydraulic power transmissionincluding a pressure cylinder, the combination with a pressure releasebypass valve communicating with said cylinder, of a remotely positionedelectrically actuated signal element, a source of electric current incircuit with said element, a switch in said circult, means forsupporting said switch in open circuit position, and a member associatedwith said means and valve for receiving the impact of fluid releasedfrom said valve to move said means in position to release said switchand permit it to move to circuit closing position.

5. In an alarm device for stokers having a hydraulic power transmissionincluding a pressure cylinder, the combination with a pressure releasebypass valve communicating with said cylinder, of a remotely positionedelectrically actuated signal element, a source of electric current incircuit with said element, a switch in said circuit, means forsupporting said switch in open circuit position, a member associatedwith said means and valve for receiving the impact of fluid releasedfrom said valve to move said means in position to release said switchand permit itto move to circuit closing position, and a plungeroperatively associated with said switch for returning it to circuitbreaking position.

6. In an alarm device for stokers having ahydraulic power transmissionincluding a fluid pressure cylinder, the combination with a pressurerelease bypass valve communicating therewith, of a remotely positionedelectrically actuated signal element, a source of electric current incircuit with said element, a switch in said circuit, an electric motorconstituting the source of power for said transmission in circuit withsaid source and switch, a movable member normally engaging said switchto support it in sig nal circuit open and motor circuit closed position,and a cup connected with said movable member in position to be moved bythe impact of fluid released from said valve to cause said member torelease said switch and permit it to close the circuit through saidsignal and open the circuit through said motor.

7. In an alarm device ior stokers having a hydraulic power transmissionincluding a fluid pressure cylinder, the combination wilih a pressurerelease bypass valve communicat ng therewith, of a remotely positionedelectrically-actuated signal element, a source of electric current incircuit with said element, a switch in said circuit, an electric motorconstituting the source of power for said transmission in circuit withsaid source and switch, a latch pivotally mounted on said transmissionnormally'engaglng said switch to support it in position wherein saidalarm circuit is broken and said motor circuit is closed, a cup mountedon the pivotal mounting of said latch in position to be moved by theimpact of fluid released from said valve to cause said latch to releasesaid switch and permit it to move to close the circuit through saidelement and open the circuit through said motor, and a manually actuatedplunger positioned to move said switch from its unlatched position tolatched position for breaking the alarm circuit and closing the motorcircuit.

JOHN ROLAND.

